It is becoming increasingly desirable to calculate a value of consumption (for example electricity consumption) or a charge (the cost of consumption) relating thereto in a technically efficient manner and where the price (the per unit price) from which the charge is derived relates to a period other than the period during which the consumption is recorded.
Various systems are used to measure quantities over time. An example is the measurement of utility supply such as electricity. Such measurements provide a recorded value corresponding to a period of time (the Metered Period), potentially where the Metered Period is not continuous.
This measured value is then frequently combined with other data that relates to the same period as the Metered Period of the measured value. In the case of electricity supply (or the supply of other utility services) the measured value of consumption can be combined with a unit price for the Metered Period to produce a price, or charge, for the supplied electricity.
The present system proposes to use information relating to sub-periods of the Metered Period, or the Metered Period itself, to calculate a rate of measurement (or rate of consumption). The system then proposes means that use this rate of consumption to overcome various technical difficulties in prior art systems. The system is principally detailed by reference to electricity supply although it can be applied to a range of other measurement systems.
At present the supply of electricity and other utilities, such as gas, is commonly metered at various points within the associated distribution network, including the consumer premises.
For the supply of gas and electricity there are generally three forms of metering. The first is a single-rate meter which simply records the total cumulative consumption. Second is a multi-rate meter which accumulates consumption into one of a number of values (registers) depending upon time. In this second type each register contains the cumulative consumption during the period that the register is enabled (which may be a non continuous period). The third records consumption in defined finite periods (Fixed Periods) as a series of consumption values with one value per period.
Where a meter accumulates consumption into a register, a value of consumption can be obtained for the finite period between two reading of the register by taking the difference in the register""s value at each of the readings. Irrespective of the type of metering equipment, it is therefore possible to determine a value of metered consumption for a metered supply that corresponds to a known finite period of time (the Metered Period). Where multi-rate metering is used, the Metered Period may not be continuous, as a result of the metering equipment recording consumption at different times into different registers. This is frequently referred to as xe2x80x9cswitchingxe2x80x9d, where the recording is switched periodically between different registers. Generally, at any point in time only one register is enabled for recording of consumption. Where recording of measurements in a register is periodically switched on and off, the corresponding Metered Period will not be continuous and will be the period of time during which recording in that register was enabled.
At present it is common for a variety of different forms of meter to be used within a distribution system. Different consumers will therefore have different meters, depending upon their specific requirements and history. Interconnections between different parts of the distribution network are also commonly metered with relatively advanced metering (Network Metering). Using such Network Metering it may be possible to determine, to the resolution of the Network Metering, the total consumption within a corresponding section of the distribution network (but not necessarily the consumption of a specific subsection of the consumers connected to it).
As stated, some metering can be used to record associated consumption within fixed periods of time (for example half hour periods). Thus, provided that meters are synchronised, it is possible to arrange for a plurality of such meters, each potentially situated at a separate location, to record consumption during the same fixed periods. Given that such metering is provided, it is possible for systems (including metering systems or systems associated with the meters) to combine, or use, data for a given period from more than one meter. Thus a meter outstation connected to a number of meters can retrieve data from each of the attached meters and for each period aggregate the consumption recorded by each individual meter to provide a total value of consumption for the period. It can then do this for each measurement period.
Where a wholesale market for electricity is operated, a unit price may be set for defined periods (the Accounting Periods). Even where a wholesale market does not operate, it may be desirable to account for the commodity supplied in terms of a unit price (or other parameter) specific to particular periods (these being Accounting Periods). Where metering records consumption for equivalent periods a cost can be determined for any such metered point (or collection of metered points) by multiplying the metered consumption for an Accounting Period by the unit price for the period. This necessarily requires the metering to record consumption for each Accounting Period. For a given Accounting Period it would also be possible to aggregate the consumption from such metering systems. Such a solution is possible using advanced metering but this is expensive and even on a limited scale creates technical difficulties and complexity in the recording, retrieval and processing of the metered data. Using such advanced metering it is therefore possible to determine a cost for an Accounting Period and to determine the aggregate consumption for any group of customers (providing that they have such metering).
The problem with most widespread metering systems, such as those used for utility supply, is that (1) the Metered Periods for individual metered locations are relatively long (typically months) and (2) the Metered Periods for different locations are not the same, thus not allowing aggregation of the Metered Consumption values.
The prior art means for determining a charge for an individual consumer (for example of electricity) is to derive it directly from metered date for the consumer obtained from the metering equipment at the consumer location. The charge is generally a per unit price multiplied by the value of Metered Consumption. In the prior art means the per unit price is valid for the whole of the Metered Period. The present system provides a means to derive a charge for one or more consumers where the charging interval (the time during which a particular price is valid) is not equal to the Metered Period and particularly where the charging interval is a sub-period of one or more of the metered periods.
A system is proposed in patent apply no WO 95/26065, 28.09.1995 (PCT/GB95/00636, 22.03.95) providing means to monitor an electricity distribution network and thereby to produce a value of consumption for a metered supply for a period other then the Metered Period for that supply. We will term this system the WO system.
The WO system provides various means whereby if a metered location accounts for a given fraction of the network demand during the Metered period of the particular metered location, then a value of consumption can be apportioned to a sub-period of the Metered Period (provided that a value of network demand is available for the period) by apportioning a similar fraction of the location""s metered consumption. Where metered data is not available for some part of the network demand, the system further provides means to estimate consumption for those consumption points for which metered data is unavailable and to adjust these estimates so that in aggregate they equal the network demand not accounted for by metered data.
The WO system is dependent for its operation upon the use of Network Metering for defined finite periods in order to determine the total electricity consumption within an electricity distribution network.
The WO system considers the situation where metering exists that can be configured for defined periods and where metering at different locations within the distribution network can be synchronized and configured to record consumption during the same periods. Using this system, processing specific to the individual Metered Period is required to produce a value of consumption for a sub-period of the Metered period. Thus processing must be repeated if another value of consumption is required for a second sub-period of the Metered period. This produces complexities, and may be inefficient, when applied on a large scale or where different metered locations are not capable of providing metered consumption for the same metered periods.
The present system is intended to deal primarily with metering systems that simply provide cumulative total consumption in one or more registers. To support such metering equipment, the present system provides a technically efficient means to calculate a rate of consumption that can be used for a number of purposes including producing a value of consumption for a sub-period of the Metered Period. However, the same rate of consumption value can be used to produce separate values of consumption for a number of sub-periods. The rate of consumption only needs to be generated once and is the only processing that is specific to the individual Metered Period. This represents a significant technical innovation compared to the WO system.
Generally speaking, the prior art systems can be classified into three forms.
In a first general form of prior art system, a plurality of metering systems are synchronized and arranged to each record consumption during the same finite periods. It is possible to aggregate the values of metered consumption obtained from such meters.
A second form of prior art system broadly produces a value of charge by using per unit pricing that is applied to metered data from either an individual meter or meter register or the aggregate value of metered consumption for a finite period for a plurality of metered supplies, where the metering is arranged to record consumption at each of the metered supplies during the same finite periods. The per unit price is constant for the whole of the Metered Period.
A third form of prior art system is the WO system.
The general intention of the present invention is to provide a means to calculate values of consumption and/or charge for periods other than the Metered Period and without reference to Network Metering, thereby overcoming the limitations of the second and third forms of known system. The present system also enables data (rate of consumption) relating to different metered locations to be aggregated even where the associated Metered Periods are different (thus removing the limitation of the first form of known system. Additionally, the present system does not require Network Metering to operate, so overcoming the limitation of the third form of known system. The present system is intended to provide a system that is technically more efficient than the WO system when dealing with general metering (where metered locations usually have different Metered Periods).
The present system recognises that the majority of installed meters do not, or cannot, currently record consumption during fixed periods (such as Accounting Periods). Generally most meters are read manually by a person visiting the meter and visually, or by hand-held unit, reading the metered data. Naturally, where meters only record cumulative consumption the Metered Period of two meters are unlikely to be the same. The present system proposes means to determine:
a rate of consumption;
a value of consumption for a period other than the Metered Period;
a charge for a period (whether or not the period equates to the Metered Period) based upon prices specific to periods which are not the metered period;
a means for producing a value of consumption (demand) representing more than one metered location where metered consumption is not available from each metered location for the same period of time;
a means for data from more than one location to be aggregated prior to calculating a charge even where the Metered Periods are not the same; and
a means for adjusting the above in dependence to the demand within a part of the distribution network.